Joint filling composition



If.. LI

United States Patent 3,279,934 Patented Oct. 18, 1966 "ice , x e) aw .c.c.- J

roller or even by blowing with a device of the cement gun 3,279,934type. The water is allowed to evaporate whereupon the JOINT FILLINGCOMPOSITION Harry R. Schuppner, Jr., El Cajon, Calif., assignor to KelcoCompany, San Diego, Calif., a corpo on f Delaware 5 No Drawing. FiledDec. 23, 1963, Ser. 0. 332,903

Claims. (Cl. 10685) This application is a continuation-in-part ofcopending application Serial No. 158,640, filed December 5, 1961, entitled Joint Filling Composition, and now abandoned. This inventionrelates to cementing compositions and more especially to improvedaqueous finishing cements of the type including an inorganic mineralfiller and additives for improving adhesion and workability.

In the art of rendering smoothly finished surfaces, especially thesurfaces of interior structures such as walls, ceilings, and the like,workers are regularly confronted with the problems of filling a cavity,of cementing units together or both. To meet these problems workerscustomarily turn to what may be called finishing cements, especially inthe construction and finishing of wallboard type surfaces. Suchfinishing cements may be understood to generally include a finely groundmineral filler such as limestone or the like, an aqueous vehicle inwhich the filler is to be suspended for easy applicability and, often, asuitable binding agent compatible with the aqueous vehicle, such as aglue or the like. The plasticity of the cement thus derived makes it aptfor filling depressions in a surface; for example, for filling-in cracksand wall joints, for hiding nail holes, for repairing minor cracks incementitious or plaster walls and like purposes. Such finishing cementsare sometimes known as spapklingcompounds, joint compounds, toppingcements, crack-fillers, plastic cements, wall joint fillers, and thelike. Such finishfiller compositions are also used as surface-texturingmaterials such as in a wall-paint to render a stippled or roughenedtexture which both decorates a surface and hides minor blemishes,especially on wallboard, concrete, or plaster type walls.

Illustrative of the problems associated with these compositions arejoint-compounds for use with wallboard (i.e., plaster-integrant panels,used in dry-wall construction) for interior wall and ceiling surfaces.These joint-compounds are a filler material which is adapted to fill thejoints be tween panels and thereby cement them together in place as wellas to fill cavities or cracks in and between the panels, and to imbedreinforcing paper tape along the joints between the panels. This tape isoften cemented in combination with metal (outside) corners and must bondsecurely with them. A finer and smoother joint compound is often usedwhereby to provide a smooth cementitious covering or topping over suchsurfaces as rough-cemented joints (as a base), and nail-holes or othercavities in plaster panels. Such a use of a plastic joint-compound ismore completely described in US. Patent 2,456,269 to Gill. Products ofthis type are generally made by preparing a dry mixture of a suitablemineral filler, including limestone, silica, clay, pyrophyllite, slate,asbestine, mica, and the like, naturally all ground to a considerablefineness, generally below 200 mesh, with a suitable binding agentcompatible with water. For use, the so described mixture is worked upwith sufficient water to yield a trowelable consistency. It is thenapplied to the wall joints or hairline cracks to be filled, mostgenerally with a trowel, or, where the same mixture is used as a surfacecoating, it is applied to the surface by such known means as a paintbinding agent included in the formulation sets the applied material to ahard rocklike mass.

While it may at first appear simple, it is not easy to formulate afiller of the type described which fulfills the necessary functionsideally. One of the greatest difficulties encountered is shrinkage upondrying, which naturally defeats the purpose of a joint filler in thefirst place,

namely, to form an unbroken contour in the treated surface. Anotherproblem commonly encountered is the lack of suitable thixotropic andworkability properties, which, when ideally present, will permit easyapplication, by troweling or otherwise, and with instantaneous cling andset-up as soon as the trowel is removed.

In the use of a plastic finishing cement, it is commonly a vexingproblem to apply the wet cement properly to a substrate. If the cementis sprayedon (e.g., with a cement gun) the flow-resistance of the highlyviscous cement under pressure quite often is a problem. A compositionwhich will not flow easily and evenly through the pressurized lines isobviously unsatisfactory for spray-on applications. On the other hand,filling compositions are commonly applied with a trowel, or other bladedtool, and for this, must exhibit good cling (i.e., not flow or run whendeposited upon a surface) as well as ready workability under the actionof a trowel, for instance. Prior art cements having the desired clingare not satisfactorily workable and too viscous for good spray-on usage.The invention has provided these contrary features, however.

For example, finishing cements are commonly carried by a worker on aflat dispenser plate known as a masoners hawk," having a handleunderneath whereby the worker may balance a quantity of cement on theplate as he moves about applying portions to a wall or other treatedsurface with a trowel or broad knife. For instance, such a worker mightbe filling nail-holes or touching up a plasterboard Wall. Workers in theart recognize that when a supply of the cement material is placed uponthe hawk to be carried thereon and worked therefrom, it must set-up andhold together, lest it run and drip from the hawk. ogether well evenwhen a wker sily a ladde ion provided by the addition of a Xanthomonascolloid according to the invention provides this internal cling to acement.

Cling properties are also critical for aqueous cements as they areapplied to a substrate. Good substratecling is necessary to providecontrol of the cement, keep it in place and prevent creep or sag, forinstance, when wet cement is slapped against a smooth vertical wall.This substrate cling requires not only that the cement should adhere toa wall surface, but that it should set-up so that a glob of the materiallaid on a surface does not flow-out onto surrounding areas but maintainsits conformation, substantially as applied. Without such control ofcement morphology, applying it is a messy proposition, as workers in theart today know since they must regularly contend with poor cling.Aqueous finishing cements such as joint compounds for wallboard panelsare sometimes seen oozing down vertical walls, dripping upon newly-laidfloors, furniture, etc., and staining them badly. Poor cling also makesit difficult for a worker to manipulate wet cement after he has appliedit to a surface, i.e., to spread it out evenly to exactly the place anddepth he desires. The invention renders this substrate-cling where theprior art cannot.

Poor substratecling becomes even more critical when applying wet cementto an overhead surface, such as to a ceiling. himself and his loadedhawk while shuffling along a staging or up a ladder as he reaches out,directing all of his attention to filling a nail-hole or mending acrack; but the job becomes impossible if, in addition, the cement wontbehave when he manipulates it. Yet it is a great deal to ask of a cementthat it set-up quickly and cling well, to any overhead surface for atime while a worker applies it, spreads it out, smooths it, andgenerally works it.

For instance, in the art of finish-cementing upon a wallboard ceiling,it is customary, as noted in the aforementioned Patent 2,456,269, tocover and reinforce the joints between adjacent wallboard panels byimbedding a perforated tape therebetween with a joint cement. To do thisa worker must first arrange a staging running along under the joints sothat he can reach them to apply his cement; then, picking up his hawkwith one hand and piling a supply of wet cement on it, he must climb upupon the staging and, reaching upward, spread the cement evenly alongthe joint while he shufiies precariously along the staging. As can beimagined, such a performance comes dangerously close to walking atightrope blindfolded. Hence, one can understand the consternation ofthe performer when his material wont set up upon the joint surfaces ashe slaps it up there, but instead drips, oozes, and slides in alldirections down upon him, upon the staging, and upon the floor. Ofcourse, poor cling will also give a worker the added problem of jugglingan cozy supply of material upon the smooth surface of his hawk. Hence,it will be appreciated that in the art workers depend heavily upon goodcling in a cement which is still not overly viscous and workable with atrowel.

This needed cling must persist for a time also, since workers mustcustomarily lay the cement along a crack in one continuous run and then,returning, smooth it out and feather it at the edges. For a long crackthis can involve at least a minute or so during which the cement shallstay in place, even on an inverted (e.g., ceiling) surface.

The necessary cling must also hold true, even when a very thin coatingof cement is rendered, as for example, where a cemented crack seam isfeathered or tapered at its edges to merge imperceptibly with thesurrounding surface. It is obvious that only a cement having goodworkability as well as good cling can be so feathered and render acoating that is both smooth flowing and highly adherent. Thiscombination of good cling with good trowelability, while extremelyimportant to workers in the art is not easy to satisfy. The presentinvention has taken a giant step toward giving a filling compositionthis exacting cling requirement along with the necessary workabilitycharacteristics.

Present-day joint compositions do not provide these characteristicsadequately. Many workers refuse to use wallboard and the attendant jointcompositions in home construction because of the mess caused by drippingcement. Where it is used on walls and ceilings in new homes, such drywall construction has heretofore required costly delays in installingfinish materials, such as hardwood floors, finished plumbing, wood trim,or the like which would be stained and marred by dropped gobs of thetypically caustic joint composition. Applications, despite all care,commonly cast such droppings about as they finish wallboard walls andceilings. The dropped material is quite disagreeable as it may be highlycorrosive to many surfaces such as fine woods or painted metals,discoloring them, etc., and is difficult to remove once it has hardened,as it quickly does. Furthermore, the drippiness" and poor cling ofpresent day joint compositions make them very unsatisfactory for use inminor repair jobs within a furnished dwelling where any dropped It isditficult enough for a worker to balance material will likely damage.This is especially so when applied by the novice or home-handyman.Hence, the present invention in improving cling markedly contributestoward making such compositions acceptable in a wide variety of uses andmakes them practicable for a wider market such as the do it yourselfmarket which is burgeoning today.

In all of these applications for finishing cement, it will be apparentto those skilled in the art that a versatile and widely useful cementmust meet other demanding requirements. Such finishing cements mustoffer: ready solubility in aqueous suspensions at all temperatures;homogeneous suspension of heavy mineral material; easy workability andapplicability, being easily laid down with a spray gun or a blade;excellent cling to a working substrate, especially if a smooth metalsurface such as a nailhead is involved; spreadability or trowel-abilityunder the action of a trowel blade whereby the cement will feather-outsmoothly to merge with the substrate; hardening to a smooth, hardsurface; good adherence to such diverse substrates as fibrous (e.g.,paper or wood) ceramic (e.g., plaster or cement) plastic and metal (suchas a nailhead of a steel corner); relative quick-drying; easily-sandedto a fine-grained finished surface which can be painted and which willmerge into a smooth adjacent substrate giving a monolithic effect so asnot to show through a paint cover; resistance to chemical reactionswhich might discolor the finished surface, such as with applied paintsor with atmospheric vapors, as from a gas stove; edge and crackresistance; having good stability in its suspending powers and itsviscosity despite extremes of temperature, despite diverse chemicaladditives and after long-aging; and other like characteristics apparentto those skilled in the art. Therefore, when one attempts to modify andimprove such a plastic filling composition with an additive to improveits workability and cling, his improved composition must also satisfythese stringent requirements. Adding a Xanthomonas hydrophilic colloidaccording to the present invention has surprisingly rendered such acomposition.

Hence, it is an object of this invention to provide an improved additivefor aqueous finishing cements and a method for preparing them wherebyimproved applicability is realized.

Another object is to provide cements having both improved workabilityand cling.

Another object of the invention is to provide a stable cement mixturehaving satisfactory suspension, temperature and chemical stability whichis much superior in applicability.

Yet another object is to provide a cement mixture, and a method forpreparing the same, having superior workability for trowel or spray-onuses and having improved stability under a broad range of changingtemperatures and pH, as well as having better suspensionstability duringextended storage.

Still another object is to provide a stable cement mixture hlvhlgsuperior cling.

Still another object is to provide a stable cement mixture which iseasier to spray or trowel-on.

An object of the present invention is to provide a wall joint cementwhich is highly thixotropic, resistant to shrinkage upon drying, andcapable of forming a hard rock-like mass upon drying.

Another object of the invention is to provide a wall joint filler whichcan be readily emplaced and is yet free of any tendency to sag, creep orflow subsequent to initial positioning, especially on vertical walls.

Other objects of the invention will appear as the description thereofproceeds.

Generally speaking, and in accordance with an illustrative embodiment ofmy invention, I incorporate powdered mineral, for example limestoneground to pass 200 mesh, with a water-compatible adhesive such as soyaprotein, casein, and the like, with a modicum of the hydrophilic colloidelaborated by the bacterium Xanthomonas campestris, and with sufiicientwater to form a trowelable mass.

In accordance with our invention, we have found that the foregoingobjectives may be achieved by incorporating a relatively small amount ofa Xanthomonas hydrophilic colloid material into conventional aqueouscement mixes. Suitable amounts of such Xanthomonas material in cementscomprising simple aqueous solutions have been found to be generally inthe range of from about 0.1 to about 5.0 percent by weight of the said.solution. A preferred range is from about 0.6 to about 1.2 percent byweight of the solution. In cements comprising an aqueous solutionincluding inert fillers, this range is modified to from about 0.05% toabout 1.5% by weight of the solution; the range of from about 0.5% toabout 1.0% being preferred.

For example, I may take from 50 to 95% of a suitable powdered mineralfiller, to which is admixed from 0.1 to 1.0% Xanthomonas campestrishydrophilic colloid, and the balance a water-compatible adhesive of thetype in the range of 1% to 8% desired. Preferably all of theseingredients are dry and comminuted, so that they may be blended to givea uniform, apparently homogeneous powder. Sufficient water is added withstirring to give the proper consistency for use. It will be understoodthat the amount of water will vary, depending upon the type of mineralfiller used, the type of water-compatible adhesive used, and theirrelative proportions. In most cases, however, for each 100 parts of drymix, somewhere between 40 and 60 parts of water, by weight, will befound to be suitable.

By proceeding in accordance with the invention, remarkable propertiesare obtained in the mixture as prepared for application, in that a lightbut adequate body is formed which suffices to hold the mixture in place,wherever it is put, even on vertical surfaces, and even in considerablethickness. At the same time, the mix is slippery to the trowel, lackingadherence to the trowel and coming away clean so that a smooth surfacecan be troweled without any pits. As is well known, even to amateur andoccasional workers in the field, if ordinary plaster is mixed with waterso that it achieves sufficient plasticity to stay where put, then ittends to grab the surface even of a smooth trowel, and it is verydifiicult to trowel to a uniform smooth surface.

The above is one of the preferred examples of my inventive cementadditive, namely, a Xanthomonas campestris hydrophilic colloid. Thismaterial is a polymer containing mannose, glucose, potassium gluconateand acetyl radicals. In such a Xanthomonas colloid, the potassiumportion can be replaced by several other cations without substantialchange in the property of the material for the instant purposes. Thismaterial, which is a high molecular weight, exocellular material, may beprepared from the bacterium Xanthomonas campestris, by whole culturefermentation of a medium containing 2% to 5% commercial glucose, organicnitrogen source, dipotassium hydrogen phosphate and appropriate traceelements. The incubation time is approximately 96 hours at 28 C.,aerobic conditions. In preparing the Xanthomonas colloid as aforesaid,it is convenient to use corn steep liquor or distillers dry solubles asan organic nitrogen source. It is expedient to grow the culture in twointermediate stages prior to the final innoculation in order toencourage vigorous growth of the bacteria. These stages may be carriedout in media having a pH of about 7. In a first stage, a transfer froman agar slant to a dilute glucose broth may be made and the bacteriacultured for 24 hours under vigorous agitation and aeration at atemperature of about 30 C. The culture so produced may then be used toinnoculate a higher glucose (3%) content broth of larger volume in asecond intermediate stage. In this stage, the reaction may be permittedto continue for 24 hours under the syinm carhonate (Xanthan gum )derivedfrom Xanthomonas camper- -tri same conditions as the first stage. Theculture so acclimated for use with glucose by the aforementioned firstand second stages is then added to the final glucose medium. In theaforesaid method of preparing a Xanthomonas campestris hydrophiliccolloid, a loopful of organism from the agar slant is adequate for thefirst stage comprising 200 milliliters of the said glucose media. In thesecond stage the material resulting from the first stage may be usedtogether with nine times its volume of a 3% glucose media. In the finalstage, the material produced in the second stage may be admixed with 19times its volume of the final media. A good final media may contain 3%glucose, 0.5% distillers dry solubles, 0.5% dipotassium phosphate, 0.1%magnesium sulphate having seven mols of water of crystallizationandwater. The reaction in the final stage may be satisfactorily carriedout for 96 hours at 30 C. with vigorous agitation and aeration. Theresulting Xanthomonas campestris colloidal material which I have foundto be particularly suitable for my purpose can be recovered byprecipitation in methanol of the clarified mixture from thefermentation. This resulting material may be further characterized as ahydrophilic colloid or gum produced by the bacterium species Xanthomonascampestris.

Alternative Xanthomonas colloidal material was prepared by repeating theabove preparation procedure with certain other known Xanthomonasbacteria, namely with: Xanthomonas incanae, Xanthomonas carotae,Xanthomonas begoniae, Xanthomonas phaseoli and Xanthomonas malvacerarum.

However, these alternative Xanthomonas hydrophilic colloid materials arenot full equivalents, i.e.-, they must be substituted in differentproportions from that of the Xanthomonas campestris. Accordingly,equivalent Xanthomonas colloids found satisfactory for substitution forthe campestris variety in the examples to be described hereinafter arelisted below in Table I. Listed also are the relative proportionsgenerally substituted for one part Xanthomonas campestris.

TABLE I Xanthomonas colloid equiva- Substituent colloid lents werederived from: quantity, parts X anthomonas campestris Xanthomonasmalvacerarum 1.25 Xanthomonas carotae 1.25 Xantlmmonas begoniae, strain3 1.65 Xanthomonas begoniae, strain 9 1.1 Xanthomonas incanae 1.5Xanthomonas phaseoli 1.1

The following are further examples of finishing cements illustrating myinvention:

Example I Percent CaCO 200 mesh 67.2 Casein-mm. 8 5

Mica-325 mesh 10 Clay-Georgia kaolin, 300 mesh 5 0.5

Use 70 parts water to 100 parts of the dry cement for good workingconsistency. Blend thoroughly each hour during usage.

Alternative Xanthomonas hydrophilic colloids were also used in thiscement formulation, namely colloids derived from malvacearum, begozziae,carotae, incanae and phaseoli strains of Xanthomonas, adjustingconcentrations as indicated in Table I.

Each of these additives, according to the invention improved theworkability of this cement and, in addition,

were observed to reduce water-separation and give good cling.

Example II Mix: Lbs. CaCO minus 200 mesh 50.0 Casein, minus 50 mesh 4.0

Soya protein, minus 50 mesh 2.0 Mica, minus 240 mesh 10.0

Talc, minus 240 mesh 5.0 Clay, minus 300 mesh, Georgia kaolin 28.0Sodium carbonate 0.5 Xanthom0nas incanae hydrophilic colloid 0.45

To 100 parts of this dry mix I add 55 parts of water to obtain theproper consistency for use. The pH is adjusted with a small amount ofsodium carbonate apt for this casein-soya protein adhesive system.Different additives will be apt for other cements or other ahesives.

Example 111 Mix the above together in the order shown, blending well.

Other cement formulations like those above may be made to incorporatethe invention by merely substituting another Xanthomonas colloidalmaterial as indicated in Table I, varying proportions accordingly.

The aqueous cements prepared according to the above formulations werefound to exhibit the superior workability and cling characteristics ofthe invention when applied to a substrate. The cements were found to berelatively smooth and workable during application, but immediatelythereafter set up to the extent that a good dripless cling was produced,thereby keeping the cement in place when applied and of the thicknesslaid on. In addition, the cements exhibited superior trowelabilitycharacteristics, whereby the applied glob of cement could be made tospread smoothly and evenly feathered out.

When applied to vertical surfaces, no sag or drip was found, whereas fora prior art cement of the same workability (lower viscosity) this wouldbe expected. The basic ingredients of aqueous finishing cements for usewith the invention will comprise an aqueous medium as the continuousphase of a solution and mineral filler ingredients as the dispersedphase thereof, together with various addition agents, such as theinventive applicationpromoters, binding agents, e

A wide variety of mineramay be used, including limestone, silica, clay,pyrop yllite, slate, asbestine, mica, barite, and the like. Some ofthese will have greater water absorption than others. For example,asbestine will generally require a higher percentage of water thanground silica.

The cemenr adhesive, may be vegetable delike, will likewise employ theinventive addition agents with similar advantageous results. Cementsincorporating a Xanthomonas colloid in accordance with my inventioninclude virtually all such compositions wherein it is desired to improveapplicability, workability, cling properties and spreading propertieswithout any deterioration in suspending properties, in viscosity or thelike.

It will be understood that while there have been described hereincertain specific embodiments of this invention, it is not intended thatthe invention be limited to or circumscribed by the specific detailsgiven in view of the fact that this invention is susceptible of variousmodifications and of changes in materials and in proportions, inpreparation and application, these changes being apparent to thoseskilled in the art, as falling within the spirit and scope of thisdisclosure and of the claims appended hereto.

I claim:

1. A hydraulic finishing cement consisting essentially of:

from about 35% to about 70% cementitious mineral materials, saidmaterials being selected from at least two from the group consisting oflimestone, clay, silica, pyrophyllite, asbestine, mica, pumice andbarite,

a minor portion in the range of 1% to 8% of a cement binder,

and coniaming a small quantity of a Xanthomonas hydrophilic colloid,said colloid being selected from the group consisting of X anthomonascampestris, X anthomonas incanae, X antlzomonas begom'ae, Xanthomonascarotae, Xanthomonas phaseoli, and Xanthomonas malvacearum colloid, saidquantity comprising less than about 5% and more than .1% by weight ofsaid cement, and sufiicient to give the cement improved application andworkability properties.

2. A dripless water base cement mix consisting essentially of:

a major portion in the range of 50% to of finely ground cementitiousmaterial, said material being selected from the group consisting oflimestone, silica, clay, pyrophyllite, asbestine, mica, pumice, andbarite,

from about 1% to about 8% by weight of said mix of a cement binder and,

from about 0.1% to about 5.0% by weight of said mix of a Xanthomonashydrophilic colloid selected from the group consisting of Xanthomonascampestris, Xanthomonas incanae, Xanthomonas begoniae, Xanth0m0nascarotae, Xanth monas phaseoli, and Xanthomonas malvacearum colloid, saidquantity being sufiicient to give the cement improved cling andworkability.

3. A dripless water base cement mix consisting essentially of:

a major portion in the range of 50% to 95 of finely ground cementitiousmaterial selected from the group consisting of limestone, silica, clay,pyrophyllite, asbestine, mica, pumice, and barite,

from about 1% to about 8% by weight of said mix of a cement binder, saidbinder being selected from the group consisting of casein, zein, soybeanderivatives, starches, sodium polyacrylate and cellulose ether, and,

a small quantity in the range of .1% to 1.5% of a Xanthomonashydrophilic colloid selected from the group consisting of Xanthomonascampestris, Xanthomonas incanae, Xanthomonas begoniae, Xanthomonascarotae, Xanthomonas phaseoli, and Xanthomonas malvacearum colloid, saidquantity being sufficient to give the resulting cement suspensionimproved cling and workability.

4. A dripless hydraulic cement mix comprising:

from about 10% to 70% of inert powdered cementitious material selectedfrom the class consisting of sentially of:

9 limestone, silica, clay, pyrophyllite, asbestine, mica, pumice, andbarite,

from about 1% to about 8% of a cement binder, said binder being selectedfrom the group consisting of casein, zein, starches, soybeanderivatives, sodium polyacrylate and cellulose ether, and,

less than about 5% by weight and more than .1% by weight of said mix ofa Xanthomonas hydrophilic colloid selected from the group consisting ofXanthomonas campestris, Xanthomonas incanae, Xanthomonas begoniae,Xanthomonas carotae, Xanthomonas phaseoli and Xanthomonas malvacearumcolloid, said quantity being sufficient to give the cement improvedcling and workability.

5. A dripless aqueous cement suspension consisting esfrom about 35% toabout 70% by weight of said suspension of powdered cementitious materialselected from the group consisting of limestone, silica, clay,pyrophy-llite, asbestine, mica, pumice, and barite,

from about 1% to about 8% of a cement binder,

a small quantity of a Xanthomonas hydrophilic colloid selected from thegroup consisting of Xanthomonas campestris, Xanthomonas incanae,Xanthomonas begoniae, X anthomonas carotae, X anthomonas phaseoli, andXanthomonas malvacearum colloid, said quantity being from about 0.1% toabout 5.0% by weight of said suspension suflicient to give resultantcement suspension improved cling and workability, and,

sutficient of an aqueous medium to render said suspension of a pasty,workable plasticity.

6. A dry hydraulic cement mix consisting essentially of:

from about 50% to about 95% powdered cementitious material by weight ofsaid mix, said material selected from the group consisting of limestone,silica, clay, pyrophyllite, asbestine, mica, pumice, and barite, andsaid material being ground to below 200 mesh fineness,

from about 1% to about 8% by weight of said mix of a cement binder and aquantity of a Xanthomonas hydrophilic colloid selected from the groupconsisting of Xanthomonas campestris, Xanthomonas incanae, Xanthomonasbegoniae, Xanthomonas carotae, X anthomonas phaseoli, and Xanthomonasmalvacearum colloid, said quantity being less than about 5% by weightand more than .1% by weight of said mix, and sutficient to produce aresultant cement suspension having improved cling and workability.

7. A dry water-base cement mix consisting essentially from about 50% toabout 95% of powdered cementitious material by weight of said mix, saidmaterial including a major portion of lime and cementitious reactantsselected from the group consisting of limestone, silica, clay,pyrophyllite, asbestine, mica, pumice, and barite,

from about 1% to about 8% by weight of said mix of a cement binder, saidbinder selected from the class consisting of casein, soybeanderivatives, zein, starches, cellulose compounds, and sodiumpolyacrylate and from about 0.3% to about 1.5% by weight of said mix ofa Xanthomonas hydrophilic colloid selected from the group consisting ofXanthomonas campestris, Xanthomonas incanae, Xanthomonas begom'ae, Xanthomonas carolae, Xanthomonas phaseoli, and Xanthomonas malvacearumcolloid, said quantity being substantially all concentrations ofadditive ingredients con- 5 sisting essentially of:

from about 50% to about 95% of cementitious materials by weight of saidmix, said materials selected from the group consisting of calciumsilicates and calcium aluminates,

from about 1% to about 8% by weight of said mix of a cement binder, saidbinder selected from the class consisting of casein, soybeanderivatives, zein, starches, cellulose ether, and sodium polyacrylateand from about 0.1% to about 5.0% by weight of said mix of a Xanthomonashydrophilic colloid selected from the group consisting of Xanthomonascampestris,

Xanthomonas incanae, Xanthomonas begoniae, Xanthomonas carotae,Xanthomonas phaseoli, and Xanthomonas malvacearum colloid, said quantitybeing sufiicient to give resultant cement suspension improved cling andworkability, said Xanthomonas colloid further being wholly compatiblewith all of saidadditive ingredients. 9. A wall joint cement suspensionconsisting essentially from about 25% to about 48% of finely groundcementitious materials by weight of said suspension, said materialsbeing selected from at least two from the group consisting of limestone,silica, clay, pyrophyllite, slate, asbestine, mica, barite, and mixturesthereof, said material being ground to below 200 mesh fineness,

a small amount of Xanthomonas campestris hydrophilic colloid in theproportion of from about 0.1% to about 5.0% by weight' of saidsuspension,

from about 1% to about 8% by weight of said suspension of a cementadhesive chosen from the class consisting of casein, zein, starches,cellulose,'ether, sodium polyacrylate soybean derivatives and mixturesthereof,

and water sulficient to yield a pasty, workable plasticity to saidsuspension.

10. A hydraulic finishing cement consisting essentially from about 35%to about of an essentially inert mineral filler,

from about 1% to about 8% by weight of cement binder,

a quantity in the range of .l% to 5% of a Xanthomonas hydrophiliccolloid, and

sufficient water to render said cement of a putty consistency.

References Cited by the Examiner UNITED STATES PATENTS ALEXANDER H.BRODMERKEL, Primary Examiner. 0 D. J. ARNOLD, Assistant Examiner.

8. A HYDRAULIC CEMENT MIX WHICH IS COMPATIBLE WITH SUBSTANTIALLY ALLCONCENTRATIONS OF ADDITIVE INGREDIENTS CONSISTING ESSENTIALLY OF: FROMABOUT 50% TO ABOUT 95% OF CEMENTITIOUS MATERIALS BY WEIGHT OF SAID MIX,SAID MATERIALS SELECTED FROM THE GROUP CONSISTING OF CALCIUM SILICATESAND CALCIUM ALUMINATES, FROM ABOUT 1% TO ABOUT 8% BY WEIGHT OF SAID MIXOF A CEMENT BINDER, SAID BINDER SELECTED FROM THE CLASS CONSISTING OFCASEIN, SOYBEAN DERIVATIVES, ZEIN, STARCHES, CELLULOSE ETHER, AND SODIUMPOLYACRYLATE AND FROM ABOUT 0.1% TO ABOUT 5.0% BY WEIGHT OF SAID MIXOF AXANTHOMONAS HYDROPHILIC COLLOID SELECTED FROM THE GROUP CONSISTING OFXANTHOMONAS CAMPESTRIS, XANTHOMONAS INCANAE, XANTHOMONAS BEGONIAE,XANTHOMONAS MALYACEARUM COLLOID, SAID QUANTITY BEING SUFFICIENT TO GIVERESULTING CEMENT SUSPENSION IMSUFFICIENT TO GIVE RESULTANT CEMENTSUSPENSION IMPROVED CLING AND WORKABILITY, SAID XANTHOMONAS COLLOIDFURTHER BEING WHOLLY COMPATIBLE WITH ALL OF SAID ADDITIVE INGREDIENTS.